Improved tool CLI.

neelance · neelance · commit da075debc443 · 2013-10-24T19:46:30.000+02:00
diff --git a/tool.go b/tool.go
@@ -3,6 +3,7 @@ package main
 import (
 	"code.google.com/p/go.tools/go/exact"
 	"code.google.com/p/go.tools/go/types"
+	"flag"
 	"fmt"
 	"github.com/neelance/gopherjs/translator"
 	"go/build"
@@ -13,7 +14,87 @@ import (
 	"path"
 )
 
+type Mode int
+
+const (
+	Build Mode = iota
+	Run
+	Install
+)
+
 func main() {
+	flag.Parse()
+
+	cmd := flag.Arg(0)
+	switch cmd {
+	case "build":
+		err := Do(Build, flag.Arg(1))
+		HandleError(err)
+		os.Exit(0)
+
+	case "install":
+		err := Do(Install, flag.Arg(1))
+		HandleError(err)
+		os.Exit(0)
+
+	case "run":
+		err := Do(Run, flag.Arg(1))
+		HandleError(err)
+		os.Exit(0)
+
+	case "tool":
+		tool := flag.Arg(1)
+		toolFlags := flag.NewFlagSet("tool", flag.ContinueOnError)
+		toolFlags.Bool("e", false, "")
+		toolFlags.Parse(flag.Args()[2:])
+		if len(tool) == 2 {
+			switch tool[1] {
+			case 'g':
+				err := Do(Build, toolFlags.Arg(0))
+				HandleError(err)
+				os.Exit(0)
+			}
+		}
+		fmt.Fprintln(os.Stderr, "Tool not supported: "+tool)
+		os.Exit(1)
+
+	case "help", "":
+		os.Stderr.WriteString(`GopherJS is a tool for compiling Go source code to JavaScript.
+
+Usage:
+
+    gopherjs command [arguments]
+
+The commands are:
+
+    build       compile packages and dependencies
+    install     compile and install packages and dependencies
+    run         compile and run Go program
+
+`)
+		os.Exit(0)
+
+	default:
+		fmt.Fprintf(os.Stderr, "gopherjs: unknown subcommand \"%s\"\nRun 'gopherjs help' for usage.\n", cmd)
+		os.Exit(1)
+	}
+}
+
+func HandleError(err error) {
+	if err == nil {
+		return
+	}
+	if list, isList := err.(translator.ErrorList); isList {
+		for _, entry := range list {
+			fmt.Fprintln(os.Stderr, entry)
+		}
+		os.Exit(1)
+	}
+	fmt.Fprintln(os.Stderr, err.Error())
+	os.Exit(1)
+}
+
+func Do(mode Mode, filename string) error {
 	b := &Builder{
 		BuildContext: &build.Context{
 			GOROOT:        build.Default.GOROOT,
@@ -31,28 +112,21 @@ func main() {
 	}
 
 	var pkg *BuilderPackage
-	cmd := "help"
-	if len(os.Args) >= 2 {
-		cmd = os.Args[1]
-	}
-	switch cmd {
-	case "install":
-		buildPkg, err := b.BuildContext.Import(os.Args[2], "", 0)
+	switch mode {
+	case Install:
+		buildPkg, err := b.BuildContext.Import(filename, "", 0)
 		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(1)
+			return err
 		}
 		pkg = &BuilderPackage{Package: buildPkg}
 		if pkg.IsCommand() {
 			pkg.PkgObj = pkg.BinDir + "/" + path.Base(pkg.ImportPath) + ".js"
 		}
 
-	case "build", "run":
-		filename := os.Args[2]
+	case Build, Run:
 		file, err := parser.ParseFile(b.FileSet, filename, nil, parser.ImportsOnly)
 		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(1)
+			return err
 		}
 
 		imports := make([]string, len(file.Imports))
@@ -62,7 +136,7 @@ func main() {
 
 		basename := path.Base(filename)
 		pkgObj := ""
-		if cmd == "build" {
+		if mode == Build {
 			pkgObj = basename[:len(basename)-3] + ".js"
 		}
 		pkg = &BuilderPackage{
@@ -75,47 +149,20 @@ func main() {
 				PkgObj:     pkgObj,
 			},
 		}
-
-	case "help":
-		os.Stderr.WriteString(`GopherJS is a tool for compiling Go source code to JavaScript.
-
-Usage:
-
-    gopherjs command [arguments]
-
-The commands are:
-
-    build       compile packages and dependencies
-    install     compile and install packages and dependencies
-    run         compile and run Go program
-
-`)
-		os.Exit(0)
-
-	default:
-		fmt.Fprintf(os.Stderr, "gopherjs: unknown subcommand \"%s\"\nRun 'gopherjs help' for usage.\n", cmd)
-		os.Exit(1)
 	}
 
 	err := b.BuildPackage(pkg)
 	if err != nil {
 		if err == PkgObjUpToDate {
-			os.Exit(0)
-		}
-		if list, isList := err.(translator.ErrorList); isList {
-			for _, entry := range list {
-				fmt.Fprintln(os.Stderr, entry)
-			}
-			os.Exit(1)
+			return nil
 		}
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
+		return err
 	}
 
-	switch cmd {
-	case "build", "install":
+	switch mode {
+	case Build, Install:
 		if !pkg.IsCommand() {
-			os.Exit(0) // already stored by BuildPackage
+			return nil // already stored by BuildPackage
 		}
 
 		webMode := false
@@ -125,17 +172,15 @@ The commands are:
 		}
 
 		if err := os.MkdirAll(path.Dir(pkg.PkgObj), 0777); err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(1)
+			return err
 		}
 		var perm os.FileMode = 0666
 		if !webMode {
 			perm = 0777
 		}
 		file, err := os.OpenFile(pkg.PkgObj, os.O_RDWR|os.O_CREATE|os.O_TRUNC, perm)
 		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(1)
+			return err
 		}
 		if !webMode {
 			fmt.Fprintln(file, "#!/usr/bin/env node")
@@ -144,15 +189,15 @@ The commands are:
 		fmt.Fprintf(file, "var Go$webMode = %t;\n", webMode)
 		file.Write(pkg.JavaScriptCode)
 		file.Close()
-	case "run":
+
+	case Run:
 		node := exec.Command("node")
 		pipe, _ := node.StdinPipe()
 		node.Stdout = os.Stdout
 		node.Stderr = os.Stderr
 		err = node.Start()
 		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(1)
+			return err
 		}
 		fmt.Fprintln(pipe, `"use strict";`)
 		fmt.Fprintln(pipe, "var Go$webMode = false;")
@@ -161,5 +206,5 @@ The commands are:
 		node.Wait()
 	}
 
-	os.Exit(0)
+	return nil
 }
